The interface is drawn with egui on OpenGL, and libmpv renders video into the same window. Network and disk work runs on a tokio runtime, off the thread that draws, so the window never waits on the server. An idle window requests no frames, so it uses next to no CPU.
rust/app/src
├── main.rs startup and wiring
├── api.rs, api/ Jellyfin HTTP client
├── features/ what the app does: sign-in, pages, playback, settings
├── services/ artwork cache, session storage, mpv, the playback proxy
└── ui/ everything on screen (the only code that uses egui)libmpv is loaded the first time something plays rather than linked, which removes 70–80 ms of dynamic linking from every launch. docs/PERFORMANCE.md in the repository records what was measured and why each optimization works.